Device for Decontaminating Surfaces

ABSTRACT

Surface blasting device using a jet of compressed air, fine grain blasting materials and liquid, said device comprising a frame, a first reservoir for storing a fluid put under pressure by a pump, a second reservoir for storing a fine grain blasting materials pressurized by compressed air means, a motor, blasting means, cooling means, an alternator, energy storage means for supplying the device with energy and connecting means for connecting the blasting means with the first and second reservoir. The blasting means comprise a blasting nozzle with an outer body having a tapered bore which extends over the full length of the outer body, said nozzle being arranged on a handle provided with a trigger, said handle being connected to the connecting means to turn the liquid and the compressed air/blasting materials mixture on or off.

The present invention relates to a surface blasting device, using a jet of compressed air, fine grain blasting materials and liquid, said device comprising a frame, a first reservoir for storing a liquid put under pressure by a pump, a second reservoir for storing a fine grain blasting materials pressurized by means of compressed air, a motor, blasting means, means for cooling, an alternator, energy storage means for supplying the device with energy and connecting means for connecting the blasting means with the first and second reservoir.

It has been known for several years the use of devices for cleaning surfaces, including building facades or monuments which are defaced due to years, atmospheric pollution or even voluntary attacks (graffiti). Such devices essentially use of a jet of compressed air, blasting particles commonly known as fine granulate and a liquid which is, in most cases, clear water. Apart from the various means of the device for the supply of air, water and fine particles, an important element of this device is the blasting nozzle of a gun handle. The nozzle has a very important function: its design and its geometry allow the jet to rotate about a rotation axis, which induces a friction movement on the surface to be cleaned. The nozzle undergoes wear, be it by the presence of the fine particles and the pressure at which these particles are submitted.

High abrasion resistant materials are usually used. However, after a number of uses, it is necessary to replace the nozzle so that the effectiveness of the jet is not reduced.

A first object of the invention is to provide a device comprising a nozzle with an improved service life. A second object of the invention is to provide a device with improved efficiency while minimizing noise. In addition, this device is arranged inside a vehicle for transportation. A third object of the present invention is to provide intensive and industrial use of the device when arranged inside the transportation vehicle, that is to say to prevent malfunctioning or engine failure that would be due to the confined and superheated atmosphere inside the vehicle. The length of the transportation vehicle can thus be reduced and it is easier to park and drive it in an urban environment. A fourth object of the invention is to improve the service life of both the device and the much less polluted transportation vehicle. A fifth object of the invention is to provide an easy to use, ergonomic and helpful device, which can be started by an operator without losing time.

The blasting device according to the present invention is characterized in that the blasting means comprise a nozzle provided with an outer body having a tapered bore extending the full length of the outer body, said nozzle being arranged on a handle provided with a trigger, said handle being connected to the connecting means to turn the liquid and the compressed air/blasting materials mixture on or off.

According to the invention, the cooling means may comprise a first, a second and a third fan.

According to the invention, the device may include an alternator.

According to the invention, a polyester cover may be arranged on the frame to partially cover the device.

According to the invention, the device may comprise a third reservoir for storing a liquid.

According to the invention, the device may comprise means connected to the air compressor for drying the compressed air.

According to the invention, the second reservoir may include a metering valve.

According to the invention, the connecting means may comprise a first pipe for transporting the compressed air/blasting materials mixture from the second reservoir to the handle and a second pipe for transporting the liquid from the first reservoir to the handle.

According to the invention, the energy storage means may include a battery.

The invention will be better understood by those skilled in the art upon reading the detailed description of an embodiment taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of the blasting device according to the invention,

FIG. 2 is a diagram showing some components of the blasting device according to the invention,

FIG. 3 is a schematic view of a control means of the blasting device according to the invention,

FIG. 4 is an axial sectional view of the blasting nozzle.

The blasting device 101 shown in FIG. 1 comprises a frame 102 on which the components of the device are arranged and a polyester cover 103 partially covering the device. The cover 103 provides for effective sound insulation and allows the device to be used in urban areas, day or night. Cover 103 also has the effect of a closed enclosure around the device, which enables a better cooling of the latter. The chassis 102 of the blasting device enables it to be arranged on or inside a light vehicle such as a van, a truck, etc.

The device comprises a reservoir 104 for storing a fine grain blasting materials, commonly referred to as granulate, for example of calcite. Polyester cover 103 covers the whole device except the blasting materials reservoir 104, thus allowing for the filling of the reservoir with no need to opening the cover. Reservoir 104 is provided with a flexible latex seal (not shown) which allows the closure of the reservoir to a much lower pressure. One can thus use the device with a low pressure when it is switched on. The reservoir 104 is provided with a metering valve for adjusting the flow rate at the outlet of the reservoir.

The device comprises a plurality of pipes 105 whose one end is connected to a control handle 301 (shown in FIG. 3). The device is used to direct, by means of the handle, a jet of compressed air mixed with granulate and water on a surface to be cleaned.

The device is provided with an exhaust 106 for removing gases generated by the combustion of agricultural diesel used by the device. The device comprises a water reservoir 107 and a fuel reservoir 108 of agricultural diesel.

FIG. 2 shows a diagram in which the various components covered by the cover 103 are illustrated.

The device comprises a motor 201 having an output of 28.8 CV. Said motor output is oversized to supply the air compressor 202 and the heat engine, but also to allow the heat generated by the rotating parts of the group to be extracted outside said group at a speed and a power sufficient to be expelled outside of the transportation vehicle. This engine also drives electric or hydraulic accessories and runs at a speed of 2800 RPM. The motor drives air compressor 202 for blasting materials reservoir 104 to be pressurized and drives a high pressure pump 203 for the water reservoir 107 to be pressurized.

The pump 203 delivers a pressure of about 100 to 170 bars for a rate of 8 to 12 liters per minute, thereby increasing the capacity of rinsing after the blasting of the surfaces. The pump 203 is provided with a filter (not shown) of 120 micrometers disposed at the inlet of the pump to protect the pump from impurities contained in water. The pump is provided with a drain valve to provide the hydraulic circuit with freeze protection and also to allow addition/suction of complementary compounds in water.

The motor 201 is connected to the exhaust 106 in order to evacuate the motor gas outside of the device. This exhaust can be advantageously connected to a coupling which allows the gas to be evacuated outside the transportation vehicle of the device. The motor 201 is arranged on the frame 102 by four rubber mounts to reduce vibration of the frame and thus reduce noise.

The device further comprises an alternator 204, oversized with respect to that is needed to start the engine. The alternator loads a battery 205 that provides the energy necessary for operation of the device. The battery 205 can also be used to power any tool or site lighting.

In order to work in any season for a long time and prevent a thermal switch to be triggered, the device comprises three autonomously driven fans. The first fan 206 provides for a 4000 m 3/hour air flow rate to cool the motor 201. The second fan 207 provides for a 3200 m 3/hour air flow rate to cool the compressor 202 and supply it with fresh air, which increases the efficiency of the compressor.

The third fan 208 provides for a 7500 m3/hour air flow rate to cool the whole enclosure closed by cover 103. Said third fan also supplies the other two fans with a forced regular air stream and provides for fresh air for the rotating parts. The three fans are jointly operated to optimize the cooling of the device. Calories which result from thermal radiation of parts of the device are easily expelled and this prevents passive air to be recycled in the device during suction. As a result, the device is suited to be used in hot or very wet countries and quality problems of expelled air are avoided.

The device comprises a radiator/heat exchanger 209 which lowers the temperature of the compressed air and dries it. This radiator thus reduces a possible clogging of the blasting materials reservoir and the pipes which transport the compressed air/blasting materials mixture to the handle.

FIG. 3 shows the control means of the blasting device according to the invention.

The control means comprises a handle 301 which is connected to a first pipe 302 which transports the material blasting materials/compressed air mixture to the handle. The handle is further connected via a second pipe 303 to the high pressure pump and a third pipe 304 is used to connect the handle to a pneumatic circuit which controls the compressor 202. The handle is provided with a trigger 305 to turn the blasting materials/compressed air mixture or water off or on. The handle is provided with a blasting nozzle 306 which will be described in more detail in connection with FIG. 4. The handle holds an elbow 307 provided with a valve to rinse the cleaned surface with water under pressure, without using the nozzle. It brings autonomy to the operator and enables energy adjustment of the device remotely from its workstation.

FIG. 4 is an axial sectional view of the end of the control means which holds the blasting nozzle.

The end of the control means comprises a rear body 401 adapted to be connected to the handle 301 and a front body 402 in which the blasting nozzle 403 is fitted. The front body 402 is secured to the rear body 401 by a screw 405. The rear body 401 includes a mixing chamber 406 having a first and a second conical portion. The mixing chamber 406 is supplied with compressed air/blasting materials mixture by means of an angled inlet fitting 407 connected to reservoir 104 by a pipe which transports the blasting materials/compressed air mixture. A longitudinal bore 408 provided with a non-return valve 404 is used to connect the mixing chamber 406 to the under pressure water pipe. The blasting nozzle 403 is fitted in the front body 402, at the opposite end of the mixing chamber 406. Once assembled, the blasting nozzle 403 is pressed against the mixing chamber output 405.

The blasting nozzle comprises an outer body with a tapered bore 409 which extends along the entire length of said outer body. The conical shape of the bore avoids a pressure drop between the mixing chamber and the blasting nozzle. The blasting nozzle is fitted within the front body which is secured to the rear body by a screw 405. This arrangement allows easy replacement of the nozzle or any other part of the nozzle, in the event of wear.

Similarly this arrangement significantly increases the service life of the nozzle, by 50% to 100%, by rotating by 120° the mixing chamber and the nozzle with respect to the nozzle body, that regularly gives wear parts an oval shape. 

1. Surface blasting device using a jet of compressed air, fine grain blasting materials and liquid, said device comprising a frame, a first reservoir for storing a fluid put under pressure by a pump a motor, a second reservoir for storing a fine grain blasting materials pressurized by compressed air, blasting means, cooling means driven by the motor, connecting means for connecting the blasting means with the first and second reservoir, the blasting means comprising a blasting nozzle with an outer body having a tapered bore which extends over the full length of the outer body, said nozzle being arranged on a handle provided with a trigger, said handle being connected to the connecting means to turn the liquid and the compressed air/blasting materials mixture on or off, characterized in that it comprises a compressor driven by the motor and controlled by the handle through a pneumatic circuit to put the blasting materials reservoir under pressure.
 2. Surface blasting device according to claim 1, characterized in that the cooling means comprise a first, a second and a third fan.
 3. (canceled)
 4. Surface blasting device according to claim 1, characterized in that it comprises a polyester cover arranged on the frame. 5-9. (canceled) 